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Biologically Inspired Robotics Laboratory

Department of Engineering

Hot Glue Kit

Hot-Glue-Kit is a soft robotics toolkit intended to allow its user to build, actuate, control and simulate soft robots in a very short time. With this kit, users can build their robot prototypes, observe and analyse their unpredicted behavior and design their second and further generations of robots within multiple iterations. This toolbox comes with hardware and software elements, and design documents which can be used to fabricate other necessary pieces.


The whole toolkit can be classified into 3 main parts: the robot construction, actuation and simulation.

Robot Construction

The main innovation comes from the usage of hot melt adhesives (HMAs) for the construction of main robot structure. The thermoplastic and thermoadhesive properties of the HMA allows the fast and easy fabrication of soft robot prototypes by extruding and gluing custom continuum pieces. HMA is also elastic which allows the users to explore the possible deformations their robot can undergo. By exploiting these properties, users can build soft robot prototypes with complex geometries, continuum limbs and joints by means of minutes. Same properties allow the easy addition or removal of parts from the robot for improvements and corrections for the next robot construction iteration. more ...


Soft joints work different than typical translational or rotational joints where the axis of motion if well defined. Unlike those, soft joints incorporate virtually infinite degrees of freedom during their motion therefore need a special actuator. Regarding this necessity, our toolkit provides a wireless actuator module which can drive tendon cables for the actuation of fabricated robots. Tendons are intuitive solutions to soft actuation as they are soft continuum structures which can conform to and actuate soft robots. The module is small (3x4x5 cm) box and can easily be glued on the robot and the tendons can be routed through teflon coated tubes. Users can build as many actuator modules as they like to explore more complex actuation. The modules implement a position control for a motor which can pull up to 11N. Different actuation modes can be controlled by sending commands from a PC with a wireless connection. more ...


One of the hardest challenges in the soft robotics field is to model and capture the rich interaction based behaviors of the physical robots, and simulate them. This generally requires complex mathematical and modeling process which results in a cumbersome, computation heavy simulator with complicated user interface. However, in order to reach a larger audience, hot glue kit offers a simple simulation library which uses (2nd gen) Sim Mechanics tool of MATLAB to simulate the soft robots and tendon modules. The library allows the construction of soft robots by a combination of many small rigid cubes that are attached to each other with spring damper systems. Tendons can be attached to these structures to model the actuation provided in the tool kit. more ...

Case Studies

Hot Glue Kit is developed as a joint project with the members of Bio-Inspired Robotics Lab in ETH Zurich and Biologically Inspired Robotics Laboratory in University of Cambridge. A simple case study in Cambridge University on building and simulating a soft robot can be found here.

As a part of Robosoft Community Action, Hot Glue Kit is disseminated in Soft Robotics Week in Livorno, Italy in 13-17 April,2015. Spring school participants are asked to use this toolkit to build robots which can walk, crawl or run on various surfaces, and simulate their robots. After approximately 10 hours of active hands on session, participant teams are asked to compete each other with their robot designs. Details about this dissemination and media from competitions can be found here.


Hot Glue Kit is an open source educational project, therefore all design files and necessary documentation is provided online. While materials related to each topic can be found in corresponding sections in "Robot Construction", "Actuation", "Simulation". A complete list of materials and necessary documents can be found here.